diff options
Diffstat (limited to 'arch/sparc64/kernel/kprobes.c')
| -rw-r--r-- | arch/sparc64/kernel/kprobes.c | 69 |
1 files changed, 63 insertions, 6 deletions
diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index b9a9ce70e55c..ffc7309e9f22 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -6,9 +6,11 @@ #include <linux/config.h> #include <linux/kernel.h> #include <linux/kprobes.h> +#include <linux/module.h> #include <asm/kdebug.h> #include <asm/signal.h> #include <asm/cacheflush.h> +#include <asm/uaccess.h> /* We do not have hardware single-stepping on sparc64. * So we implement software single-stepping with breakpoint @@ -302,16 +304,68 @@ static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + const struct exception_table_entry *entry; + + switch(kcb->kprobe_status) { + case KPROBE_HIT_SS: + case KPROBE_REENTER: + /* + * We are here because the instruction being single + * stepped caused a page fault. We reset the current + * kprobe and the tpc points back to the probe address + * and allow the page fault handler to continue as a + * normal page fault. + */ + regs->tpc = (unsigned long)cur->addr; + regs->tnpc = kcb->kprobe_orig_tnpc; + regs->tstate = ((regs->tstate & ~TSTATE_PIL) | + kcb->kprobe_orig_tstate_pil); + if (kcb->kprobe_status == KPROBE_REENTER) + restore_previous_kprobe(kcb); + else + reset_current_kprobe(); + preempt_enable_no_resched(); + break; + case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SSDONE: + /* + * We increment the nmissed count for accounting, + * we can also use npre/npostfault count for accouting + * these specific fault cases. + */ + kprobes_inc_nmissed_count(cur); + + /* + * We come here because instructions in the pre/post + * handler caused the page_fault, this could happen + * if handler tries to access user space by + * copy_from_user(), get_user() etc. Let the + * user-specified handler try to fix it first. + */ + if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) + return 1; - if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) - return 1; + /* + * In case the user-specified fault handler returned + * zero, try to fix up. + */ - if (kcb->kprobe_status & KPROBE_HIT_SS) { - resume_execution(cur, regs, kcb); + entry = search_exception_tables(regs->tpc); + if (entry) { + regs->tpc = entry->fixup; + regs->tnpc = regs->tpc + 4; + return 1; + } - reset_current_kprobe(); - preempt_enable_no_resched(); + /* + * fixup_exception() could not handle it, + * Let do_page_fault() fix it. + */ + break; + default: + break; } + return 0; } @@ -324,6 +378,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; + if (args->regs && user_mode(args->regs)) + return ret; + switch (val) { case DIE_DEBUG: if (kprobe_handler(args->regs)) |